Recently affiliates of co.cc might have received a "Malware Detected" page on browsing to the Referrals section of the co.cc website.The screenshot attached is from Google Chrome.
On browsing to http://www.co.cc/affiliates/affiliates.php, the user is warned that the website contains content
The link in question is used in a reference to an animated gif used as a display banner to promote co.cc on publisher websites. One of the embeddable links that co.cc presents on the affiliate page also includes the link in question. Apparently the website lookfeel-201002[dot]co(dot)cc that co.cc uses to serve the banner has been labelled as a site serving malware.
The Google Safe Browsing advisory report gives further details.It says that the site was found to host malware and infect a website 1 time in the past 90 days. It rates the website as suspicious.
If publishers have been using this embed link to promote co.cc, users to their websites too might get the same warning page. The other embeddable link which is a iframe, however seems unaffected.
Co.cc seems to have corrected the problem, by skipping the page in question altogether. You are now taken to the login page directly and once logged in, you can see the sign up list upfront. This leaves the question,where do people get their banners from?